Burglar-alarm.



PATENTED AUG. 2'7, 1907.

N. L. B. DOLL.

BUBGLAR ALRM.

APPLICATION FILED DBO. 1x, 1905.

"TLSON L. B. DOULL, Ol." LOS ANGELES. C filill? BURG-Lltu. 155.1151212.

No. scossa Application llecl Desserte-'1.1, 1905. Serial lio. 291,352

Speoiceton of Letters Feten-t.

ed ilus". 2'?, 1907.

To all whom 'it may concern.:

Be it known that I, NELSON L. B. DOULL, a citizen of ("ranuda, residing at Los Angeles, in the county'ol' Los Angeles and State of California, have invented new and useful Improvements in Bu1glar-Ala1Ins, of which the following is a specification.

My invention relates to an electrica-ily operated alarm; and the object thereof is to provide an improved alarm device which may he set to sound an alarm when either the latch or the locking bolt is moved not quite hir enough to perinitlthe door to be opened il the same constituted the sole means lor securing the door closed. I accomplish this object by the mechanism described herein and illustrated in the accompanying drawings in which:-

Figure -1- is a portion ot' a door and lock and :i portion of my alzirm device in section. Fig, 2- is u side elevation oi a part of my alarm device. Fig'. 3- is a scction on the line 3 3 of Fig. 1. Fig. 4 is s side elevation of certain of the plates shown in Fig. 1

In the drawings 5 is the door to which is secured the lock (i having latch 7 and locking holt S, which lock is.Y of any construction provided with these parts. Theyv door jamh 9 is provided with the ordinary latch plate l0 secured thereto by the ordinary screws 11. Extending fromfthe latch socket 12 in the door anb is a recess 13 in which is mounted a casing 14 which is preferably circular and exteriorly threaded so as to hold it securely in place in recess 13 into which it is screwed. In the outer end of this casing is secured a. plug 15 composed of insulating material. Through this plug extend the screws 16 and 17. To the head'of screw 16 is fastened a wire 18 which passes through the jamh, and is secured to a plate 19, which plate is secured to the Casement 20 secured to the outer case or" the jsnih, or the plate might'be secured to the jarnb itself. 'lo screw 17 is secured wire 2l which passes through the janlb and is secured to plate 22 preferably secured to the easement in close proximity' to plate 19, but separated therefrom. Extending from the lock holt socket 23 in the door jamb is a recess 24 in which is mounted a casing 25 which is preferably circular and cxteriorly threaded so as to hold it securely in placen the recess 2e into which it is screwed. In the outer end of this casing is screwed a plug 26 composed of insulating material. Through this plugextend screws 27 and 28. To the head' of screw 27 is fastened a. wire 29 which passes through the jainb and is secured to plate 19. To the head of screw 2S is fastened a. wire 30 which is secured to plato-22.

1u a portshle'case 3l 1s secured a hattery preferably composed of a dry cell 32. One pole pf this battery is connected loy wire' 33 to switch plug 3d. The other pole o the battery is connected by wire 35 to switch 49 which is connected to the alarni hell S6. This switch may he used to open and close the circuit when the apparatus is used lor a length oi time in one situation. 'The other side of alarm hell 36 is connected hy wirr,A 37 to switch plug 38. Plate 19 has a slot 39, the upper part 39 of which is larger than the bottom part and is large enough receive and' to permit to pass therethrough either ol' the plugs 34 or 38. Plate 22 has a slot Li0 therethrough the upper part 40 oi which is larger than the lower portion and is sufhciontly large for the passage therethrough of either plug 34 or38. Extending through casing 14: and plug 15 is a rod 41 which has a head l2 lying within the lstch socket. To rod 41 within the casing is secured a coller Ai3 sud surrounding the rod within the casing -is a spring 44. Extending tluough casing 25 and plug 2S is a rod 45 which has a head lo which lics within the lochholt socket. Within the casing and secured to the holt is a collar 47 and below the coll-.ir and surrounding the holt is a spring 4S. .fitter the door is closed and the locking bolt is thrown to its locked position it will be seen that the latch engages 'the head ot' holt fll and prevents the collar secured thereto from engaging screws 16 and 17 and that the head oi rod 4l does not touch either of said screws. lt will also he seen that when the locking holt is thrown to locked position that it also prevents collar 47 from engaging screws 27 and 28. Now if it is desired that the occupant oi the room shall know if any one from the outside thereoic is trying' to enter the room he pushes button 34 through the upper part of the. slot in either plate "i9 or 22 and draws the wire down into the lower part of the slot so that it cannot disengage therefrom. The other button passes through the other plate and brings it down into the lower part of the slot in like manner, thereby connecting the battery and hell to plates 19 and 22. Now if some one from the outside of the room throws the locking holt so as to unlock it spring 4S will causecollar 47 to engage screws 27 and 28 thereby closing the circuit and the bell will ring. Before the locking holt is thrown if a person should turn the latch to a position in which the door would open spring es would cause coller 43 to engage screws 16 and 17. thereby closing the circuit and causing the bell to ring.

By this construction 1 have provided an eficient alarm which 'will no tify the occupant of the room whenever any one is tampering Vwith the lock thereof. As the battery and bellers portable they can he set st any place in the room and during the day time can he detached it desired and placed in a closet. lf desired my device could he permanently secured to the outside doors and s, switch provided in the place of plate i9 and another or plate 22.

By putting s. socket in a wii'zdow casing the device can he used in a window, hut in such case only one sochet need he Having described my invention what I claim as new and desire t0 securc by Letters Patent is:-

tween said plates :md i'iie battery and bell, electrical counections between plate 19 and one Contact point ,in ezx'fli of Suid pln;.';f-:A nml electrical counectimis between plate M aud the remninim,xl coulant points in the ruspe@ In witness that, l claim the foreguing I have Subscribed my name this 4th day of December, l

NELSON L. B. pinna.

'ituesses E. Hxmviiliu, M. A. .'Iorms. 

